The recommended dose of fosamprenavir (Telzir) in the European Union is 700mg with 100mg ritonavir (Norvir) twice daily in combination with at least two other antiretroviral drugs. In Europe, it is only approved for treatment-experienced patients.

Fosamprenavir is licensed in the United States for treatment-naïve or -experienced patients, at the following dosages:

• 1400mg twice a day.
• 1400mg with 200mg of ritonavir once a day, in people who have not previously taken protease inhibitors.
• 700mg with 100mg of ritonavir twice a day.

The use of a higher fosamprenavir dose in highly treatment-experienced patients is being investigated. Preliminary safety data suggest that boosting of 1400mg twice daily with 200mg of ritonavir is poorly tolerated^[1]. Boosting of 1400mg fosamprenavir with 100mg ritonavir twice daily is still being investigated but no efficacy data are available.

Unlike other protease inhibitors, a chief advantage of fosamprenavir is that it does not have any food restrictions^[2].

Fosamprenavir is available in tablets containing 700mg of the drug, and as a liquid at a concentration of 50 mg/ml.